400ex jetting

[400exracer08]

ok, i want to do this the simple way i just want to change the main jet.
400ex bored out to a 425ex
White brothers slipon
Uni air filter
no lid

what main jet do i use?

[Chino886]

Originally posted by 400exracer08
ok, i want to do this the simple way i just want to change the main jet.
400ex bored out to a 425ex
White brothers slipon
Uni air filter
no lid

what main jet do i use?

I am guessing that 170 would be a good starting point, then go up from there. What compression are you running?

[400exracer08]

i believe 12 to 1

[400exracer08]

182 main jet is a great choice. I put it in and it ran great!!!